Reference Target (Reference) - JRC JMA-5204 Instruction Manual

5.2.6 Reference Target (Reference)

This equipment can calculate and display the speed of own ship by tracking a target whose position is fixed
with respect to the ground and by setting this target as a reference target.
Attention
The reference target function is to be used if the own ship's
speed cannot be displayed normally due to trouble such as a
speed sensor malfunction. Do not use the reference target
function except in emergencies.
If the speed or course of the own ship is changed or a new
reference target is set, the displayed speed may take 3 minutes
or more to reach the specified speed after the speed / course
change or the setting.
Even after 3 minutes or more has passed, the speed may differ
from the specified speed depending on the tracking condition.
If a large radar echo such as a land target is set as a reference
target, the vectors of the speed and other tracking targets will
not be displayed correctly and may cause an accident.
If a sailing ship is set as a reference target, the vectors of the
speed and other tracking targets will not be displayed correctly
and may cause an accident.
If the REF. is selected for the speed sensor, the AIS function
cannot be turned on.
If the reference target is lost or the target tracking function is
stopped, the speed sensor is placed in manual mode MAN .
The loss of a reference target may have a major impact on the
accuracy of the results for true speed and true course of the
target and that own speed will be degraded.
The reference targets are only used for the calculation of true
speed.
5.2 TT OPERATION
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